/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/

function promiseTest(time, str) {
	return new Promise((resolve, reject) => {
		setTimeout(() => {
			resolve(str)
		}, time)
	})
}
let addStr = promiseTest(10, 'hello')
addStr.then(value => {
	console.log(value)
	let a = 'lagou'
	return promiseTest(10, value + a)
}).then(value => {
	console.log(value)
	let b = 'I ♥ U'
	return promiseTest(10, value + b)
}).then(value => {
	console.log(value)
})